Tractor



D. G. KNITTEL.

TRACTOR.

APPLMIATION FILED MAY 28, 1919 1,361,875, Patented Dec. 14, 1920.

3 SHEETSSHEET 3.

WITNESSES D. G. KNITTEL.

TRACTOR. APPLICATION FILEL MAY 28, 1919.

3 SHEETS-SHEET 2.

WITNESS KW M. I i 4 Jmwm/ I Patented Dec. 14, 1920.

D. G. KNITTEL.

TRACTOR.

APPLICATION FILED MAY 28, l9l9.

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w m \N 5 Wm W m 5 m wmE UNITED" STATES PATENT OFFICE.

DAVID G. KNITTEL, OE WILDWOOD, PENNSYLVANIA, ASSIGNOR TO KNITTEL KRAWLING TRACTOR COMPANY, OF PITTSBURGH, PENNSYLVANIA, A COR- PORATION OF DELAWARE.

TRACTOR.

Specification of Letters Patent.

Patented Dec. 14, 1920.

To all whom it may concern Be it known that 1, DAVID G. Km'r'rnn, residing at Wildwood, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Tractors, of which improvements the following is a specification.

My invention relates to tractors of the general type wherein two propelling members are, by means of a single motor, driven either simultaneously or independently in either direction to cause the tractor to move forwardly or rearwardly, or to turn in either direction.

The object of my invention is to provide improved driving connections for such trac-- tors, and improved means for operating and controlling such driving connections.

While unlimited to any specific type of tractors of the general class described, my invention is particularly applicable to tractors provided with endless-band drivers or crawlers, and is so illustrated in the accompanying sheets of drawings in which Figure 1 is a side View of the tractor; Fig. 2 a plan view thereof in which the driving connections and controlling parts are shown in horizontal'section, the general plane of View of the sectional portion being indicated by the line II--II, Fig. 1; Fig. 3 an enlarged view of the sectional portion of Fig. 2; and Fi i a sectional view taken on the line I -IV, Fig. 3. v e

The tractor which, for the purpose of illustrating my invention, is shown in the drawings, includes a frame 1 upon which there is mounted a motor 2 of any desired type and construction. From the crank or power shaft 3 of the motor" there is a sprocket chain connection 4 to a shaft 5, one end of which extends into a gear box '6. The other end of the shaft 5 may be provided I with a belt pulley 7 whereby the motor 2 may be used to drive machinery, as for ex ample a threshing machine. A shaft 8 projects from the other side of the gear box 6 and is connected by means of a sprocket chain 9 to a driving shaft 10 extending on both sides of the sprocket chain connection. Through the medium of clutch mechanism presently to be explained the driving shaft 10 imparts rotation to two driven shafts 11 and 11*, the connection bein such that the driven shafts may be rotate independently or simultaneously in either direction to propel the tractor.

The driven shafts 11 and 11 may be connected to any desired means for propelling the tractor. As shown herein they are connected toendless-band drivers 12 and 12, the ends of such shafts being provided with sprockets 13' and 13 which mesh with the links forming the endless-band drivers. Each endless-band driver extends around a pair of wheels 14 journaled in bearings 18. For the purpose of holding taut the endlessba-nd drivers, each of such bearings is provided with a pair of vertically disposed rods 20 which extend through, and are slidable within, housings 21 secured to the frame 1. Between the bearing blocks 18 and the housmgs 21 there are arranged coiled springs 22, the opposite ends of which act upon, and tend to spread apart, the housings and bearin blocks.

xtending around each endless-band driver there is a flexible cord 53 which may be formed of a wire cable, chain or other suitable flexible structure. The purpose of such cord is to prevent lateral skidding of the tractor, as fully explained in my 00- pendmg patent application, Serial No. 300,311 filed of even date herewith. No claim is made herein to the invention incident to the provision of the cord 53, such invention being claimed in my co-pending application just mentioned.

As previously stated, my invention contemplates the provision of means whereby each of the driven shafts 11, 11 may be driven in either direction either independently or simultaneously. Since the connections between the shafts 10 and 11 are the same as those between the shafts 10 and 11, the further description of such connection will be made with reference to the shaft 11.

Referring particularly to Fig. 3, the shafts 10 and 11 have arranged between them a pair of clutches, 23, 24, and 25,v 26, which are preferably conical friction clutches of the general type indicated in the drawings. The male clutch members 24 and 26 are, by means of links 27 connected to a sleeve 28 so feathered to the shaft 10 that such sleeve maybe moved longitudinally of, but will rotate with, the shaft. The female clutch member 23 is rotatably mounted on the shaft 10, while the female member 25 of the other clutch is keyed to the shaft 11, the shafts 1O and 11 being in alinement with each other as indicated in the drawings. To the clutch member 23 there is attached a pinion 29, which meshes with a pinion 30 keyed to a shaft 31, to which shaft there is keyed a second pinion 32 meshing with an idler 33, which idler in turn meshes with a pinion 34 secured to the clutch member 25.

The sleeve 28 may he slid longitudinally of the shaft 10 by means of a ring 35 rotatably mounted upon the central portion of the sleeve, such rin being engaged by a yoke 36 secured to t ie end of a controlling lever 37. Intermediate of its length the lever 37 is pivotally connected to the outer end of a worm shaft 38, as by means of a ball and socket joint 39. The worm shaft 38 has threaded engagement with the interior of a bearing block or housing 40, and its inner end is secured. to a controlling pedal preferably in the form of a bell crank lever having legs 41 and 42. As will be seen, the pitch of the worm shaft 38 is such that a partial turning of the shaft by means of the controlling pedal 41, 42, causes its outer end to move sufiiciently to cause the clutch-operating sleeve 28 to move the clutch members 24 and 26 from one to the other of their extreme positions.

As previously explained, the clutch connections between the shafts 10 and 11 are the same as those between the shafts 10 and 11. The clutch-operating sleeve 28 for controlling the clutches for driving the driven shaft 11 is, in the manner explained with reference to the sleeve 28, moved by means of a lever 37. Similarly, the movement of the lever 37' is effected by means of a foot pedal 41 42. By independently moving the foot pedals 41, 42 and 41*, 42*, the clutch controlling sleeves 28 and 28" may be so positioned that the shafts 11 and 11 may be driven independently in either direction. That the ordinary-steering of the tractor may be effected by turning a steering wheel of the character usually used in automobiles, the outer ends of the levers 37, 37 a are preferab'l'y connected to each other by means of a link 43 provided with a pin 44 engaged by the outer forked end of an arm 45 secured to a rod 46, on the upperend of which rod there is attached a steering wheel 47.

In'the drawings all the clutches are indicated as being disengaged, and in such ositions the rotation of the driving sha 10 will transmit motion to neither the shaft 11 nor 11. By turning the steering wheel 47 tothe right, or in a clockwise direction as viewed in F ig.- 3, the levers 37 and 37 will simultaneously turn upon theirintermediate pivot points with the result that the clutch members 24 and 26 will engage their cooperating clutch members 23 and 25*. The clutch connections thus established will cause the shafts 11 and 11 to be driven siearers multaneously in opposite directions with the result that the tractor will turn to the right substantially upon its vertical central a-XlS,-r it being assumed that the sprocket chain 9 is driven in the direction indicated by the arrow on Fig. 1. Similarly, the movement of the steering wheel 47 to the left will cause the shafts 11 and 11 to be driven each ina direct-ion opposite to that effected by turning the steering wheel to the right, with the result that the tractor will turn to the left.

If desired, the foot pedals 41, 42 and 41 42, may be moved to effect the same driving of the shafts 11 and 11 as just explained" with reference to the movement of the steering wheel 47. The foot pedals, however, are primarily used for the purpose of throwing the clutches so that the shafts 11 and 11 may be simultaneously driven in the same direction. Thus by moving both the pedals 42 and 42 downwardly the worm shafts 38 and 38 will be caused to move toward each other, and, through the connections already explained, the clutch members 24 and 24*- are brought into engagement with the clutch members 23 and 23 respectively. In these positions of the clutches, the driving of the shafts 11 and 11 will be effected through the shafts 31 and 31*, and the trains of gears through which such shafts operate. A downward movement of the pedals 41, 41 will effect a reverse arrangement of the shafts 11 and 11 in the reverse direction.

According to the provisions of the atent statutes I have described the princip e and operation of m invention together with the construction w 'ch I now consider to represent the best embodiment thereof. However, I desire to have it understood that, within the scope of the appended claims, my invention may be practised by other forms of construction than that specifically shown and described.

I claim as my invention:

1. In a tractor, the combination with a frame and a motor carried thereby, of a pair of rotatably driven shafts, connections including clutches between said motor and driven shafts whereby each shaft may be independently driven in either direction, pivoted controlling levers oonnectedone to each of the said clutches, a single means for op-' erating said levers simultaneously, and independent means for moving the pivot point of each of said levers whereby the clutches of each of said shafts may be separately con-' trolled.

2. In a tractor, the combination with a frame and a motor carried thereby, of a pair of rotatably driven shafts, connections including a pair of clutches between said motor and each of said shafts, pivoted controlling levers one oonnectedto oneand the other to the other of said pairs of clutches, inde pendent means for moving each of said levers whereby each of said shafts may be drixen independently or simultaneously in either direction, and means for moving said levers simultaneously.

3. In a tractor, the combination with a frame and a motor carried thereby, of a pair of rotatably driven shafts, connections including clutches between said motor and driving shafts whereby each shaft may be independently driven in either direction, a, pivoted controlling lever connected to the clutches for each of said shafts, a foot pedal for independently moving each controlling lever, and a steering Wheel connected to both levers for moving them simultaneously.

4. In a tractor, the combination with a frame and a motor carried thereby, of a pair of rotatably driven shafts, connections including a pair of clutches between said motor and each of said shafts, pivoted controlling 20 levers one connected to one and the other to the other of said pairs of clutches, connecmy hand.

DAVID (i. KNITTEL. \Vitnesses:

ALICE A. TRILL, PAUL N. CRrroHLow. 

